Timing of EEG-based cursor control.

Full Abstract

Recent studies show that humans can learn to control the amplitude of electroencephalography (EEG) activity in specific frequency bands over sensorimotor cortex and use it to move a cursor to a target on a computer screen. EEG-based communication could be a valuable new communication and control option for those with severe motor disabilities. Realization of this potential requires detailed knowledge of the characteristic features of EEG control. This study examined the course of EEG control after presentation of a target. At the beginning of each trial, a target appeared at the top or bottom edge of the subject's video screen and 1 sec later a cursor began to move vertically as a function of EEG amplitude in a specific frequency band. In well-trained subjects, this amplitude was high at the time the target appeared and then either remained high (i.e., for a top target) or fell rapidly (i.e., for a bottom target). Target-specific EEG amplitude control began 0.5 sec after the target appeared and appeared to wax and wane with a period of approximately 1 sec until the cursor reached the target (i.e., a hit) or the opposite edge of the screen (i.e., a miss). Accuracy was 90% or greater for each subject. Top-target errors usually occurred later in the trial because of failure to reach and/or maintain sufficiently high amplitude, whereas bottom-target errors usually occurred immediately because of failure to reduce an initially high amplitude quickly enough. The results suggest modifications that could improve performance. These include lengthening the intertrial period, shortening the delay between target appearance and cursor movement, and including time within the trial as a variable in the equation that translates EEG into cursor movement.

Author information

Author/s: Wolpaw, J R (JR); Flotzinger, D (D); Pfurtscheller, G (G); McFarland, D J (DJ);

Affiliation: Wadsworth Center for Laboratories and Research, New York State Department of Health and State University of New York, Albany 12201-0509, USA.

Grants: HD30146 (Agency:NICHD NIH HHS)

Journal and publication information

Publication Type: Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.

Journal: Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society (J Clin Neurophysiol), published in UNITED STATES. (Language: eng)

Reference: 1997-Nov; vol 14 (issue 6) : pp 529-38

Dates: Created 1998/05/06; Completed 1998/05/06; Revised 2007/11/14;

PMID: 9458060, status: MEDLINE (last retrieval date: 2/18/2009, IMS Date: )

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

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